Cost function for response algorithm

Abstract

A controller for an implantable blood pump includes processing circuitry configured to initiate a suction response algorithm if a combination of a number of detected suction events multiplied by a suction event variable and a number of non-suction events multiplied by a non-suction event variable exceed a predetermined threshold.

What is claimed is: 
     
       1. A controller for an implantable blood pump, comprising:
 a memory; and 
 processing circuitry in communication with the memory, the processing circuitry configured to:
 multiply a number of suction events, of one or more suction events that occurred within a predetermined time period, by a suction event cost to generate a first output; 
 compare the first output to a predetermined threshold to determine whether a suction condition has occurred; 
 determine, based on comparing the first output to the predetermined threshold, whether the suction condition has occurred; and 
 responsive to determining that the suction condition has occurred, control, according to a speed response algorithm, a speed of an impeller of the implantable blood pump to resolve the suction condition. 
 
 
     
     
       2. The controller of  claim 1 , wherein to determine whether the suction event has occurred, the processing circuitry is further configured to:
 multiply a number of non-suction events, of one or more non-suction events that occurred within the predetermined time period, by a non-suction event cost to generate a second output; 
 add the first output and the second output to generate a third output; and 
 compare the third output to the predetermined threshold to determine whether the suction condition has occurred. 
 
     
     
       3. The controller of  claim 1 , wherein the predetermined threshold is at least one. 
     
     
       4. The controller of  claim 1 , wherein the suction event cost is less than one. 
     
     
       5. The controller of  claim 1 , wherein the predetermined threshold is at least 0. 
     
     
       6. The controller of  claim 1 , wherein the processing circuitry is configured to determine each suction event of the one or more suctions events over a one-second time period. 
     
     
       7. The controller of  claim 1 , wherein the predetermined time period is 30 seconds. 
     
     
       8. A method of operating an implantable blood pump, comprising:
 multiplying, by processing circuitry of a controller for the implantable blood pump, a number of suction events, of one or more suction events that occurred within a predetermined time period, by a suction event cost to generate a first output; 
 comparing, by the processing circuitry, the first output to a predetermined threshold to determine whether a suction condition has occurred; 
 determining, by the processing circuitry and based on comparing the first output to the predetermined threshold, whether the suction condition has occurred; and 
 responsive to determining that the suction condition has occurred, controlling, by the processing circuitry and according to a speed response algorithm, a speed of an impeller of the implantable blood pump to resolve the suction condition. 
 
     
     
       9. The method of  claim 8 , wherein determining whether the suction condition has occurred comprises:
 multiplying, by the processing circuitry, a number of non-suction events, of one or more non-suction events that occurred within the predetermined time period, by a non-suction event cost to generate a second output; 
 add the first output and the second output to generate a third output; and 
 comparing, by the processing circuitry, the third output to the predetermined threshold to determine whether the suction condition has occurred. 
 
     
     
       10. The method of  claim 8 , wherein the predetermined threshold is at least one. 
     
     
       11. The method of  claim 8 , wherein the suction event cost is less than one. 
     
     
       12. The method of  claim 8 , wherein the predetermined time period is 30 seconds. 
     
     
       13. The method of  claim 8 , wherein determining the number of suction events comprises determining, by the processing circuitry, each suction event of the one or more suction events over a one-second time period. 
     
     
       14. A system comprising:
 an implantable blood pump; 
 a power source for the implantable blood pump; and 
 a controller for the implantable blood pump, comprising:
 a memory; and 
 processing circuitry in communication with the memory, the processing circuitry configured to:
 multiply a number of suction events, of one or more suction events that occurred within a predetermined time period, by a suction event cost to generate a first output; 
 compare the first output to a predetermined threshold to determine whether a suction condition has occurred; 
 determine, based on comparing the first output to the predetermined threshold, whether the suction condition has occurred; and 
 responsive to determining that the suction condition has occurred, control, according to a speed response algorithm, a speed of an impeller of the implantable blood pump to resolve the suction condition. 
 
 
 
     
     
       15. The system of  claim 14 , wherein to determine whether the suction event has occurred, the processing circuitry is further configured to:
 multiply a number of non-suction events, of one or more non-suction events that occurred within the predetermined time period, by a non-suction event cost to generate a second output; 
 add the first output and the second output to generate a third output; and 
 compare the third output to the predetermined threshold to determine whether the suction condition has occurred. 
 
     
     
       16. The system of  claim 14 , wherein the predetermined threshold is at least one. 
     
     
       17. The system of  claim 14 , wherein the suction event cost is less than one.